Tom H

I have a 2008 RX350 AWD with only 500 miles on it so far and I am starting to get concerned about what seems to be excessive slipping or a delay in response in the trans. Under normal forward driving the trans seems to shift very smooth. The problem occurs under situations where I am coming to a near stop, basically coasting, and then have to accelerate again to continue forward. This could be in a slow moving traffic type situation or when maneuvering through a parking lot. When I try to execute a small increase in speed the engine revs but the trans doesn’t respond. It’s as though it’s in neutral and unable to decide which gear it should be in. After a 2 to as long as a 5 second delay it finally engages and moves forward. The condition is even worse if I’m heading into a slight incline. Once it is engaged everything is fine and the subsequent shifts are very smooth. When starting from a complete stop it works perfectly. I’ve never had a transmission slip this much in any vehicle. There was one situation where I was almost broadsided because the RX delayed in moving forward.

I realize this is a subjective call but I’m trying to determine what level of slipping in the trans is considered normal under the conditions I’ve described. Does anyone have similar results on their 2008 RX350? I have searched and read past threads about issues with the earlier model years but I thought they were resolved by now. I haven’t taken the RX in for service yet but I fear I will get the standard “everything is working as designed” answer from my dealership.

salimshah

You may have a hardware issue with your transmission but it can be software and the input you give.

Lexus has put in adaptive learning and that has made the vehicle respond based on how you "normally" drive. If you are faced with abnormal conditions then you must give abnormal input. In other words,Normal Condition .. more gas => driver wants to speed up, so the transmission will not shift down. Abnormal condition ... middle of the cross road and you want to move quickly ... stomp on the gas all the way and the trans will respond. Try it ... it will not damage your vehicle (as long as you are in gear and not in "P" or "n".


Keep in mind the adaptive learning is reset when you remove battery for long time. So the vehicle changes its behavior and in few weeks falls into the new groove.


Salim

Tom H

Salim, thank you for your feedback. My last 5 or 6 vehicles had adaptive learning on the trans but I have never experienced anything quite like this. I believe this is a malfunction in the RX. Example: Suppose your caught up in slow moving stop and go traffic. Your moving along about 5 mph and the traffic ahead begins slowing even more. You take your foot off the throttle and begin to coast. Suddenly the traffic begins to move again and you want to nudge forward very slowly, using minimal acceleration, to stay with the pace. In that case my RX engine rpm begins to rise but the trans is in neutral. Then suddenly it decides which gear to be in and engages. That decision can take anywhere from 2 to 5 seconds in which the RX doesn't respond at all. Occasionally the cars behind me begin to use their horns to get me to get moving. I agree, if I am in a position where I can give it a lot of pedal it will quickly find a gear and go. The problem is this occurs every time I drive the RX. Even pulling out of my drive (I back in) when I begin to move forward, take my foot off the throttle, and then re-apply at a low speed the trans delays and I end up coasting out of my driveway with the engine racing as if I had pushed it into neutral and put on the gas. My last Volvo as well as my last Camry had a similar delay but it was almost imperceptible at well under 1 second. The examples I give are just a few that come to mind but this happens every day under a large variety of driving conditions.

NeverSatisfied

It won't hurt to ask! They need to help you, regardless of their opinion anyway.

Like you already know, some people (myself included), experienced a similar problem, and got the issue resolved.

Trying to think back, I believe my problem was that the tranny shifted abruptly from first to second gear in slow, stop & go traffic, AND had a throttle delay when trying to accelerate during a rolling stop. I believe there was a TSB issued, and it did work. I have never had the throttle delay happen after that. The abrupt shifting still happens, but I've learned how to control it.

Let us know what happens!

Tom H

NS,

Thanks, your comments are reassuring. I also appreciate how you seemed to use far less verbiage than I to describe the situation. I guess it's time to check in with the dealership. Fortunately they are only a few miles from my house and from work. I had a similar rough shifting (2nd to 3rd) with my Volvo XC70. I learned to live with and control it as well. I will post back as I learn more.

MC Wong

Tom_H,

I used to have a Volvo 01 xc70 and I had major tranny issues, so I end up trading the car in. But Lexus seems to share some of the Volvo tranny characteristics. I seem to have a rough downshift issues wth my 04 RX. It's always when I am slowing down where sometimes i can feel the car downshifting gears hard. Its like a jerky gear change. This always occurs during peak hour traffic or when I am about to stop at a set of traffic lights. I am still trying to control this. Any suggestions. Been to the dealer a number of times and have the latest updates but still not as smooth as I would like.

AM1

iTrader: (6)

they never fixed the tranny issues even in the rx350. it may not be as apparent or noticeable but the problems are there and the dealers know it. ASk them about it, i wonder what they will say?

lexuslover

as far as i know that is normal behavior, however the 2-5 seconds you mentioned is far too long. if people are honking at you to move along b/c your trans has not engaged a gear, then that sounds pretty dangerous to me. i feel a slight lag when doing what you describe, but nothing major, and i have felt it on newer 350 loaners and other cars.

are you sure it's really 2-5 seconds? i would say mine is .5-1 sec at most to engage and keep moving... there is a little jerk if you are trying to accelerate quickly when you've already decelerated to very slow speeds, but i think that's just the nature of this particular 5spd auto transmission. not the greatest trans out there, but i've never felt unsafe or unable to keep up with traffic in 4 1/2 years owning this car (if i did it would have been replaced a long time ago!!)

CK6Speed

iTrader: (1)

That was always my major problem with my tranny. With my wifes driving style, she used to get the tranny delay. That 1-2 seconds before anything really happened usually when trying to punch it to merge into the freeway. My drivig style though I never experienced that much at all. I did experience it, but it was rare. The one I had a problem with until the day we sold the car was that hard slamming shift at really low speeds when you want to accelerate a bit. For me, it was mostly going over speed bumps. It was like you were a novice manual transmission owner who held the clutch in too long over the bump, then realized it so just dumped the cllutch and you get that jerk. We had the latest tranny update as well. I believe my wife said she still noticed the tranny delay, but it was better after the update. Not cured though.

Also, I still like to know how these learning transmissions learn two drivers driving style and how it can quickly adapt to each on a timely manner. If more than one driver drives the car.

tgdaman

TomH,
My car is also an '08 with low miles. I have noticed some hunting for gears in city driving, but nothing that worries me. If you are in gear an push the gas, I go fine. I have learned to adjust my driving style a little. What I would like changed, however, is the fact the car doesn't shift into 5th until about 48-49 mph. I would prefer it happen at 43-44, inside the boulevard speed limits. I'm sure gas mileage would increase and I would be coasting more often and not have as much engine braking when I don't want it.

Guess I'll learn to live with that, too.

fw1

I would say I agree with lexuslover and tgdaman. Every now and then, I notice a 0.5-1 second delay in shifting from 1st to 2nd gear. This delay was more apparent within the first 1k miles because I was trying my best not to accelerate hard from rest. After that, I drove more normally and didn't seem to feel the delay as much.

teamtbo

fw1 and others, can explain the delay for me? I have a 2007 Camry XLE V6 that had a 1000 rpm shift flare within the first few days. We had the tranny replaced two months later (April). The flare came back so we had the ECU reflashed this past Friday. Yesterday, we experienced the flare again. I am hoping Toyota will buy it back in the near future. If so, I was thinking about upgrading to a RX350 but this 'delay' issue is really concerning me. Sort of sounds like a shift flare to me.

So, between 1st and 2nd gear, what is happening? Is the tranny basically shifting from 1st to neutral and the tachometer surges up but you don't move anywhere until it engages in 2nd gear? Seems like a lot of Toyota's cars are experiencing shift flare, delay and hesitation issues - Camry, Highlander, RX350....

Tom H

If I start from a complete stop with light, moderate, or slightly heavy acceleration the car moves through every gear with no delays or flaring. In fact the shift from 4th to 5th is so smooth that it can't be felt. I have to watch the tach drop to tell it shifts. But again today, while slowly cruising through a new housing development, I had slipping/delay at every slow down and turn. It was very annoying. I had at least 2 occasions where the delay was again 4 seconds. One of them occurred as I was coasting at a slow speed and then had to increase speed just slightly while entering a very slight downhill section in the road. The car wanted to coast on it's own on the decline but I needed to go just slightly faster. The 4 second delay seems like an hour. I had my windows down and you could hear the engine revving outside of the car. It was sort of an embarrassment as it drew the attention of people standing nearby.

I do believe this is a by-product of the current trends in technology because so many manufactures are experiencing this problem and few seem to have it under wraps.

teamtbo

Tom, so, during that 4 second delay, can you tell what is actually happening with the transmission? Is it like the car is in neutral and revving up until it finally engages in a gear and starts to accelerate? Or, do you think the car downshifted to 1st or 2nd gear as you were coasting...and then, it took 4 seconds for the car to upshift to the appropriate gear in order to allow you to accelerate? Does that make sense?

I am still trying to get an idea of what the car is actually doing during the delay?

AM1

iTrader: (6)

just a warning for you guys. the dealer will probably suggest doing the update for the tranny. the problem may get worse if you do that. i did it and the tech admitted that the update might make it worse and it is not reversible once its done. So do that update at your own risk. Someone mentioned the camry having the same problem, from what the techs tell me at the dealer the tranny problem is in all RX330-350's, ES330-350's, avalons,camrys, solaras, etc......common toyota problem.